Syringe with vernier adjustment



Patented Jan. 20, i953 SYRINGE WITH VERNIER ADJUSTMENT Alfred s. Howard, shaker Heights, and William Selesnick, Cleveland Heights, Ohio Application october 29, 1947, serial No. 782,844

3 Claims.

This invention relates in general to fluid measuring devices and more particularly to devices generally known as syringes and of the type adapted for use in the medical, scientific and allied professions for handling, measuring and administration of fluids.

In many chemical and biological operations avery high degree of precision in measurements of fluid volume is essential. The conventional practice of achieving such measurements is to use transparent graduated pipettes, the volumev It is, therefore, one of the primary objects of the invention to provide a mechanical hand controlled suction device capable of high precision in suction, measurement and discharge of fluids.

Another object is to provide such a syringe capable of such high precision measurements without the inherent disadvantages of fine gradations.

, Another object is to provide such a syringe that is adapted to removably receive a pipette in air tight relationship,- whereby neither the pipette holder nor vits adjustable parts need be graduated nor actually receive any iiuid in order to effect a controlled suction and measurement of fluid in the pipette or controlled discharg from the latter.

Another object is to provide an improved means 0f adjustment of the pipette holder for fluid suction and discharge control in the pipette that provides means for both coarse and Vernier like adjustment for purposes of facility and precision in operation.

With the foregoing and other objects in view, the invention resides in the combination of parts and in the details of construction hereinafter set or pipette holder, the pipette not -being showin-f Figure 2 is a view in longitudinal section taken through the pipette holder in the same retracted position shown in Figure l;

Figure 3 is a view similar to Figure 2 with the plunger extended for coarse adjustment and the thimble notas yet actuated for Vernier like adjustment;

Figure 4 is a view similar to Figure 3, showing the thimble having been extended for Vernier like adjustment for suction;

Figure 5 is a view in longitudinal section of a pipette holder having a ne Vernier like screw adjustment for the thimble and plunger and a coarse screw adjustment for the plunger, instead of the direct manual manipulation thereof, as in Figures 1 to 4, inclusive; e

Figure 6 is a view in cross-section taken along line 6 6 of Figure 5;

Figure 7 is a fragmentary view in longitudinal section taken through the thimble, grip and barrel in the suction chamber below the plunger showing a modification thereof to include the added feature of an air vent, or suction relief, the same including a small shell about the grip frictionally maintained in position but adjustable to bring about registry of apertures tov provide an air vent to the suction chamber and out of registry to prevent such air admission; and

Figure 8 is a view in section taken along line 8-8 of Figure 7.

Referring more particularly to the drawings. the new and novel syringe comprising 'the invention is illustrated with the pipette shown only in Figure 2 at 2l, it being understood that the'- pipette, itself, may be included also in the remaining gures and of any suitable conventional type and be releasably secured and held by a collet I that carries a rubber-like member 2 resting on an internal shoulder 3 and centrally apertured at 4 to receive the pipette 2l extending through the aperture 5 in the collet and through aperture 4.

This collet is internally screw-threaded to engage the corresponding external screw-threads of a hollow barrel 6 and the collet has a knurled portion 1 to facilitate relative longitudinal adjustment of the collet on the barrel 6. In practice, the collet is preferably adjusted downwardly on the barrel and the upper unrestricted end of the pipette 21 forced only a short distance` through aperture 4 of washer 2. The collet is then screwed upwardly on the barrel, bringing the lower end of the barrel 6 downwardly against the` upper bevelledend .of washer 2 'tosqueeze-l `ring I2.

3 the latter radially inwardly to more tightly engage the pipette therein.

Barrel 6 also has its upper portion externally screw-threaded to engage the internal screw threads of a hollow thimble 8 to provide for relative longitudinal adjustment between the barrel and thimble. Thimble 8 is also provided with a knurled portion 8' to facilitate such adjustment. Slidalily and rotatably-surrounding thimble 8" and collet I and pressr ilt'IV on barrel 6, is a hand grip 9 with a knurled portion |01.

Fitted in an inner annular groove in the head?v of thimble 8 is a frictional gripping, sealing ring--y II and also fitted in an inner annular groove in the upper portion of bar-riell 6i? a sealing-L15.'

ring I2 of less frictional gripping-- qualit'iesf to-v receive in air tight relationship.l a cylindricalplunger I3 having an enlarged'manually operable head I4.

Figures 1 to 4, inclusive, represent one form that the: invention may,V take.z Assuming the pipette to be gripped? by the;v washer. 2: in the collet, Figure 2 being alongitudinal.- sectional illustration' of. Figure 1, shows. the syringey to beI in normal. retracted position.. Both.r sealing rings II andV I2 are capable of air and uid. tight sealing. Sealing ring II, howeven; is..de signed. to haveV a much greater capacity for gripping the plunger.l l-.thanhasf the sealing. This being true,.the preferred: opera-l tional practice is'Y to first manually extendthe plunger. so thatl itsenlarged head is*r slightly above. the upper extremity-ot the. thimble: and. the gripping. sealing ringi II holds. the. plunger. in thisV adjusted position. ThisV affords theoperator the opportunity off manual. operation. of the plunger for uid discharge,Y which. opportunity would not be presentdfftheplunger head.- were resting on they upper end of the thimble.

The normal operationalv procedure in. sucking, in a desired volume of fluidintothe pipette is to immerse the restricted. endl thereof into' the uid. While grasping the grip 9 inone hand,v they fingers of thev same liand'mayA beemployedl to manipulate the. plunger head'. to withdraw the plunger to an extendedv position. such as that shown in Figure-.3,l duringwhich operation. aY Volume ofv iluid.. just. short. of.' that'. desired, has. been introduced into the. pipette. Inorder to obtain precision the remaining suction-action is hand operated undenvernier like. adjustment. This is accomplished.- byv releasing the plunger head. and; whilev still'. holding.. the grip I inthe.

same hand. employing. the lingers.L of. thesame hand. to rotate the.. thimble.l the appropriate direction. to extend. theI thimble.. upwardly.. to. av position as shown in Figure: 4..4

of choice to effect any desired ineness of? adi-f' justinent so as to predetermine thel rater of resulting suction of the uidinto the pipette'.V

Figures. v andA 6r illustrate` another' of.' the;

f0rms..that thefinvent'on. may take.. laerethe:rv

Due.- to. the, gripping action of. sealing ring' LI. on the. plunger, the thimble carries the plunger. upwardly-to a. position.v slightly higher than.. that. shown in..

same adjustable collet construction for holding the pipette may be employed. Fundamentally it is constructed to be capable of the same iine adjustment for suction as that described in connection with Figure 4. The main difference is the additional provision of an alternately useable high pitch coarse screw adjustment for manually actuating the suction plunger instead of the free; direct' pulling manipulatiom thereof described invconnection with Figure/r3? detail, collet I is externally screw threaded onto a hollow barrel I5 which, in turn, is internally screwedintdahollow thimble I6. A cylindrical suction plurger'II' is slidable in barrel I5 and has.: its: upper." portion enlarged and provided withlcoarse-'ihigh pitch screw threads I8 to mesh with correspondingr internal threads I9 of the upper reducedportion I6 of the hollow thimble I6.. Thet'op of plunger I'I may terminate in a hexagonal head 29 to receive a correspondingly shaped aperture in ai cap: 2l.v thatz-vslidably.. and rotatably ts.- about theupper end of thimble I5 and iss-freel from` threads. I8.: Four slots. 212- may be provided in. thethimble. in. order toproperly controlthe frictionbetweenl threads I8` of the plunger andthreads t9. of. thethimble.

The. normal operational procedure.. here is fundamentally they same.. as. that. employed. in the embodiment shown` in. Figures. 1 t'o inelusive.. The. device. may. beheldlin one. handf while the ngers. ofthe .samehand are. employed. to rotate the cap `2| in theappropriate.direction for first creating, a` friction between threads I8" and. I9 greater than. thev friction. between the plunger and grippingsealing. ring. I.I.. Continued. turningA of' thecapvin this direction results.- in` drawing the plunger. upwardly into an. extended position to. suck uidi. into. theV pipette in. a volume. just. short oil that desired,similarlyto that phase of the operation discussed in connection with Figure 3. The cap. 2| provides a; hand'screw control .which insome instances may be preferred over direct hand manipulation or direct pull on the plunger of FigureSl In Figurey 5, the subsequent Vernier lik'eadjustment is. virtually identical.. withthat-described in connectionwithFigure.4. Indetaill the grip 9 is still heldin. the. sameh'and. the ngers of which are released from the cap and.. gripped aboutthimble I6 to rotate. thesamei'n the. appropriate direction to.draw the..th`iinble upwardly duen to the...meshing. of. its-.fine threads with those of barrel i5. Thus, sensitivity, precision. and smooth. uid flow. intothepipette accomplished by a; slow. sensitivity. controlled` movementprovided. for.` by themeshing; of theN fine. pitch engaging. screwthreadsy of barrel `I5'.y and thimble. I6;

It follows. that the. same advantages/obtained by thelrinvention. inhand controlled-:smooth sensitive fluid suction flow into the pipette for meas-l urement purposes equally apply in. thev obtainingl of. the-same smooth sensitive hand controlled. fluidV discharge. from thel pipette. byV the reversal of thev adjustment ofi the' movableA partsfofsthedevice.

From the foregoing it will be seenthat there:v has been provided ai new and= novelY syringe providing for readyinstall-'ation and. removal of. a; pipette; that` no fluidneed be drawn into-the device nor need.I itbe calibrated; that itprovidesl alternately useablefhand adjustment devices for varying degrees of sensitivity and consequent hand? controlled fluid suction or discharge'bygthe merefuse of. one hand.-A

A further refinement of the device useable in any form of the invention including the modiiications shown in Figures 1 to 4, inclusive, and Figures 5 and 6, is shown in Figures 7 and 8. In the use of pipettes of the volumetric type in connection with the syringe of the present invention it has been. found that in some instances it may be desired to provide an auxiliary hand controlled air vent for introducing air into the suction chamber in the barrel below the plunger to permit drainage of the fluid from the pipette at normal pressure. In order to accomplish this, an aperture 26 may be provided in barrel 6 at a point below the maximum retracted position of the plunger. Surrounding the grip is a thin band 23 with an aperture 26. Suitable recesses are formed Iin the grip to receive an O ring 25 which bears against the exterior surface of the barrel and the interior surface of the band to frietionally maintain the band in any adjusted position, The O ring 25, moreover, provides an effective air tight seal for aperture 26 in barrel 6 from the exterior 'as long as it remains out of registry with aperture Z4 in the band 23. Relative adjustment of the band, barrel and grip may thus bring about introduction of air from the exterior into the suction chamber when desired or positively preclude such air admission thereinto during normal operation.

We claim: l

1. In a portable hand controlled fluid suction and discharge device, a hollow barrel and a plunger slidably mounted therein to provide a suction chamber in said barrel below said plunger, a collet adapted to releasably receive a pipette and longitudinally adjustably mounted on the lower end of said barrel, a hollow thimble adjustably mounted externally about the upper end of said barrel by relatively ne low pitch meshing screw threads, sealing rings carried internally by said barrel and thimble to be engaged by said plunger, the latter of which sealing rings has a relatively greater frictional grip on said plunger', said plunger being slidably moved in said barrel by manually rotating said thimble relative to said barrel, said plunger being directly manually adjustable longitudinally in said barrel by the same hand independently of relative rotation of said barrel and thimble.

2. In a portable hand controlled iiuid suction and discharge device, a hollow barrel and a plunger slidably mounted therein to provide a suction chamber in said barrel below said plunger, a thimble screw-threadedly adjustably mounted on said barrel, sealing rings carried internally by said barrel and thimble to be engaged by said plunger, the latter of which rings exerts a relatively greater gripping action on said plunger whereby said plunger is adapted to be longitudinally moved in said barrel and thus operated for uid suction and discharge by a single hand operation both by relative rotation of said thimble and barrel and by direct hand manipulation of said plunger manually with the same hand independently of relative rotation of said thimble and barrel.

3. In a hand controlled fluid suction and discharge device, a hollow barrel and a plunger slidably mounted therein to provide a suction chamber in said barrel below said plunger, a thirnble adjustably mounted externally on said barrel by relatively iine low pitch meshing threads, means for normally holding said plunger against longitudinal movement in said thimble, said plunger being manually movable longitudinally for relatively course degree of uid suction and discharge, said thimble, upon manual rotation on said barrel, being adapted, through said means, to move said plunger longitudinally for relatively ner degree of iiuid suction and discharge, hand controlled air vent means for introducing air from the exterior into said suction chamber and comprising a manually rotatable band mounted on said barrel and held thereon by frictional means, said band and barrel having registerable apertures therein leading to said suction chamber.

ALFRED S. HOWARD. WILLIAM SELESNICK.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 60,104 Wiles Nov. 27, 1866 670,868 Bode Mar. 26, 1901 1,072,636 Mueller Sept. 9, 1913 1,358,280 Bossert Nov. 9, 1920 2,250,467 Cole July 29, 1941 2,263,865 Boileu Nov. 25, 1941 2,292,617 Dana Aug. 1l, 1942 2,358,159 Gruetter Sept. 12, 1944 FOREIGN PATENTS Number Country Date 370,832 Italy May 3, 1939 

